Assessment of the protective effect of yeast cell wall ß-glucan encapsulating humic acid nanoparticles as an aflatoxin B1 adsorbent in vivo.

This study aimed to assess the protective effect of encapsulating humic acid-iron complexed nanoparticles (HA-Fe NPs) inside glucanmannan lipid particles (GMLPs) extracted from yeast cell wall against aflatoxin B (AFB1 ) toxicity in vivo. Four groups of male Sprague-Dawley rats were treated orally for 2 weeks included the control group, AFB1 treated group (80 µg/kg b.w); GMLP/HA-Fe NPs treated group (0.5 mg/kg b.w), and the group treated with AFB1 plus GMLP/HA-Fe NPs. GMLPs are empty 3-4 micron permeable microspheres that provide an efficient system for the synthesis and encapsulation of AFB1 -absorbing nanoparticles (NPs). Humic acid nanoparticles (HA-NPs) were incorporated inside the GMLP cavity by complexation with ferric chloride. In vivo study revealed that AFB1 significantly elevated serum alanine aminotransferase, aspartate aminotransferase, creatinine, uric acid, urea, cholesterol, triglycerides, LDL, malondialdehyde, and nitric oxide. It significantly decreased total protein, high-density lipoprotein, hepatic and renal CAT and glutathione peroxidase content and induced histological changes in the liver and kidney (p ≤ 0.05). The coadministration of the synthesized formulation GMLP/HA-Fe NPs with AFB1 has a protective effect against AFB1 -induced hepato-nephrotoxicity, oxidative stress and histological alterations in the liver and kidney.

Bioactive compounds from Aspergillus niger extract enhance the antioxidant activity and prevent the genotoxicity in aflatoxin B1-treated rats.

This study aimed to identify the bioactive compounds of the ethyl acetate extract of Aspergillus niger SH2-EGY using GC-MS and to evaluate their protective role against aflatoxin B1 (AFB1)-induced oxidative stress, genotoxicity and cytotoxicity in rats. Six groups of male Sprague-Dawley rats were treated orally for 4 weeks included the control group, AFB1-treated group (80 µg/kg b.w); fungal extract (FE)-treated groups at low (140) or high dose (280) mg/kg b.w and the groups treated with AFB1 plus FE at the two tested doses. The GC-MS analysis identified 26 compounds. The major compounds found were 1,2,3,4,6-Penta-trimethylsilyl Glucopyranose, Fmoc-L-3-(2-Naphthyl)-alanine, D-(-)-Fructopyranose, pentakis (trimethylsilyl) ether, bis (2-ethylhexyl) phthalate, trimethylsilyl ether-glucitol, and octadecanamide, N-(2- methylpropyl)-N-nitroso. The in vivo results showed that AFB1 significantly increased serum ALT, AST, creatinine, uric acid, urea, cholesterol, triglycerides, LDL, carcinoembryonic antigen, alpha-fetoprotein, interleukin-6, Malondialdehyde, nitric oxide, Bax, caspase-3 and P53 mRNA expression, chromosomal aberrations and DNA fragmentation. It decreased serum TP, albumin, HDL, Bcl-2 mRNA expression, hepatic and renal TAC, SOD and GPx content and induced histological changes in the liver and kidney. FE prevented these disturbances in a dosage-dependent manner. It could be concluded that A. niger SH2-EGY extract is safe a promising agent for pharmaceutical and food industries.

Isolation and molecular characterization of mycotoxigenic fungi in agarwood.

Agarwood (Oudh), is often used by people in the Kingdom of Saudi Arabia. The Oudh has been mentioned in the Hadith and is traditionally used for its aroma (perfuming smell) and potential medicinal applications. The aim of the study was to isolate mycotoxigenic fungi that grow on agarwood and the factors and storage conditions that enhance their growth potential. In addition to the detection of associated mycotoxins like: Aflatoxin B1 (AFB1) and ochratoxin A (OTA) from agarwood. Agarwood samples were collected from local markets of Jeddah governorate, Kingdom of Saudi Arabia. Standard dilution plate method was used for the isolation of fungi. Isolated fungi were identified based on morphological characteristics and confirmed using molecular biology techniques. AFB1 and OTA were detected by High Performance Liquid Chromatography (HLPC). The results indicated that the most commonly isolated fungal genera were in the following descending order: Aspergillus, Penicillium, Fusarium and Rhizopus. Among Aspergillus genera, A. flavus and A. ochraceus were detected based on their morphology and confirmed by PCR using specific primers. It was also noted that AFB1 was released by 15.3 and 55.0% of A. flavus and A. parasiticus isolates respectively with levels reaching up to 14.60 µg/L. The moisture content in the samples ranged from 3% to 10% affected fungal growth. AFB1 was detected in 22 out of 50 of the samples. The maximum level of AFB1 (50.7 µg/kg) was detected in samples with higher moisture content (12%) stored at a temperature of 32 °C. Aspergillus fungi were found to be the most predominant fungal genera found on agarwood. Moisture content (9-10%) and storage temperature (32 °C) stimulated fungal growth and their ability to produce mycotoxins. For this reason, storage conditions at the marketing place should be adequate in order not to provide a conducive environment for fungal growth which is associated with the mycotoxin production. In order to prevent fungal growth and mycotoxin production, it would be recommended to store agarwood at temperatures not exceeding 25 °C and moisture content of up to a maximum of 5-6%.

Quercetin inhibits the cytotoxicity and oxidative stress in liver of rats fed aflatoxin-contaminated diet.

This study was conducted to evaluate the protective role of quercetin (Q) against the cytotoxicity, DNA damage and oxidative stress in rats fed aflatoxin (AFs)-contaminated diet. Female Sprague-Dawley rats were divided into six groups and treated for 21 days as follows: the control group; the group fed AFs-contaminated diet (1.4 mg/kg diet); the groups treated orally with Q at low or high dose (50 and 100 mg/kg b.w.) and the groups AFs-contaminated diet plus low or high dose of Q. At the end of experiment, blood and liver samples were collected for biochemical, histological, histochemical and genetic analyses. The results indicated that animal fed AFs-contaminated diet showed significant increase in serum biochemical parameters, oxidative stress markers and DNA fragmentation accompanied with significant decrease in total proteins, GPX, SOD, DNA and RNA content and fatty acid synthase (Fas) and TNFα gene expression in the liver tissue. Q at the two tested doses succeeded to normalize the biochemical parameters, improved the content of nucleic acids in hepatic tissues, the gene expression, the histopathological and histochemical picture of the liver. It could be concluded that Q has a potential antioxidant activity, a protective action and regulated the alteration of genes expression induced by AFs.

Ability of Lactobacillus casei and Lactobacillus reuteri to protect against oxidative stress in rats fed aflatoxins-contaminated diet.

Lactic acid bacteria (LAB) have been reported to remove mycotoxins from aqueous solutions through a binding process, which appears to be species and strain specific. The aim of the current study was to evaluate the protective role of Lactobacillus casei (L1) and Lactobacillus reuteri (L2) against aflatoxin (AFs)-induced oxidative stress in rats. Sixty female Sprague-Dawley rats were divided into 6 groups including the control group and the groups treated with L1 or L2 (1 x 10¹¹/ml) alone at a dose of 10 ml/kg b.w or plus AFs (3 mg/kg diet) for 4 weeks. At the end of the treatments, blood and tissue samples were collected for biochemical and histological studies. The results indicated that AFs alone induced a significant decrease in food intake and body weight and a significant increase in transaminase, alkaline phosphatase cholesterol, triglycerides, total lipids, creatinine, uric acid and nitric oxide in serum and lipid peroxidation in liver and kidney accompanied with a significant decrease in total antioxidant capacity. Treatments with L1 or L2 succeeded to induce a significant improvement in all the biochemical parameters and histological picture of the liver. Moreover, L2 was more effective than L1 and both can be used safely in functional foods.

Antioxidant properties of Thymus vulgaris oil against aflatoxin-induce oxidative stress in male rats.

The leafy parts of thyme and its essential oil have been used in foods for the flavor, aroma and preservation and also in folk medicines. The aim of the current study was to determine the components of Thymus vulgaris L essential oil and to evaluate the protective effects of this oil against aflatoxin-induce oxidative stress in rats. Thirty six mature male Sprague-Dawley were divided into six treatment groups and treated for 2 weeks as follows: control group; the groups treated orally with low and high doses of T. vulgaris oil (5 and 7.5 mg/kg b.w.); the group fed AFs-contaminated diet (2.5 mg/kg diet) and the groups fed AFs-contaminated diet and treated orally with the oil at the two tested doses. Blood and tissue samples were collected at the end of treatment period for biochemical study and histological examination. The results indicated that the oil contains Carvarcrol (45 mg/g), Thymol (24.7 mg/g), ß-Phellandrene (9.7 mg/g), Linalool (4.1 mg/g), Humuline (3.1 mg/g), α-Phellandrene (2.3 mg/g) and Myrcene (2.1 mg/g). However, α and ß-pinene, Myrcene, α-thyjone, Tricyclene, 1, 8-cineole, and ß-sabinene were found in lower concentrations. Treatment with AFs alone disturbs lipid profile in serum, decreases Total antioxidant capacity, increase creatinine, uric acid and nitric oxide in serum and lipid peroxidation in liver and kidney accompanied with a sever histological changes in the liver tissues. The oil alone at the two tested doses did not induce any significant changes in the biochemical parameters or the histological picture. The combined treatment showed significant improvements in all tested parameters and histological pictures in the liver tissues. Moreover, this improvement was more pronounced in the group received the high dose of the oil. It could be concluded that the essential oil of T. vulgaris has a potential antioxidant activity and a protective effect against AFs toxicity and this protection was dose dependent.

Fate of aflatoxin B(1) in contaminated corn gluten during acid hydrolysis.

BACKGROUND: Aflatoxins are a group of mycotoxins that cause serious chronic disease outbreaks and contaminate several food products such as corn and its by-product, corn gluten. The aim of the current study was to evaluate the effect of hydrochloric acid (HCl) on aflatoxin B(1) (AFB(1) ) degradation in contaminated corn gluten under different HCl concentrations, hydrolysis temperatures and hydrolysis times. RESULTS: During the wet milling process the highest AFB(1) level (45.68 µg kg(-1) ) (37.86%) was found in corn gluten fraction. Treatment with 1 mol L(-1) HCL at 110 °C resulted in degradation of AFB(1) by 27.6% (33.07 µg kg(-1) ) after 4 h and reached 42.5% (26.26 µg kg(-1) ) after 8 h. Increasing HCl concentration from 1 to 3 mol L(-1) HCl resulted in increased degradation of AFB(1) , while complete degradation occurred in the presence of 5 mol L(-1) HCl after 4 h at 110 °C. Meanwhile, half-life time of AFB(1) was recorded after 2 h at 100 °C and was < 2 h at 110 °C in the presence of 3 mol L(-1) HCl. CONCLUSION: It could be demonstrated that the manufacture of hydrolyzed vegetable protein is a suitable method for decontamination of aflatoxin in highly contaminated grains, especially gluten fractions. The hydrolysis reaction could be considered in terms of first-order reaction kinetics of AFB(1) degradation.

Adsorption of sterigmatocystin by montmorillonite and inhibition of its genotoxicity in the Nile tilapia fish (Oreachromis nilaticus).

Sterigmatocystin (Stg) is closely related to the mycotoxin aflatoxin as a precursor in aflatoxin biosynthesis and classified as an IARC Group-2B carcinogen. The aim of this study was to investigate the efficacy of Egyptian montmorillonite (EM), a clay mineral, to adsorb Stg, to test the stability of the resulting complex under different conditions in vitro, and to utilize the Nile tilapia fish as an in vivo model to evaluate the protective effect of EM against Stg-induced toxicity and clastogenicity. In the in vitro study, four concentrations of EM (0.5, 1, 2 and 4 mg/L aqueous solution) and three concentrations of Stg (5, 10 and 50 microg/ml) were tested. The results show that EM had a high capacity of adsorbing Stg at different concentrations tested. The adsorption ranged from 93.1 to 97.8% of the available Stg in aqueous solutions. The complex was stable at different pHs at 37 degrees C in different organic solvents. An in vivo experiment was conducted to evaluate the ability of EM to prevent the toxicity and chromosomal aberrations induced by Stg in the Nile tilapia fish. Fish received an intragastric dose of EM in corn oil (0.5 mg/kg bw) with or without Stg (1.6 microg/kg bw) twice a week for 4 weeks. Body weight was recorded during dosing, and blood and tissue samples were collected at the end of treatment. Stg residues were determined in fish tissue. The results show that Stg was toxic and clastogenic to fish as indicated by the significant decrease of body weight and the increase in frequencies of micronucleated red blood cells (MN RBC) and chromosomal aberrations in the kidney. The intragastric administration of EM combined with Stg to fish resulted in a reduction of the number of MN RBC and the frequency of chromosomal aberrations in the kidney compared with the group treated with Stg alone. It could be concluded that EM itself was safe and successful in the prevention of Stg toxicity and clastogenicity.

Application of adsorbent agents technology in the removal of aflatoxin B(1) and fumonisin B(1) from malt extract.

The commercially hydrated sodium calcium aluminosilicate (HSCAS) and the Egyptian montmorillonite (EM) had an excellent capability of adsorbing AFB(1) and FB(1) in an aqueous solution at different tested levels. The adsorption ratio of HSCAS ranged from 95.3% to 99.1% and 84.7% to 92.4% of the available AFB(1) and FB(1) respectively. EM showed an adsorption ratio ranged from 95.4% to 99.2% and 78.2% to 92.2% for AFB(1) and FB(1) respectively. Both adsorbents were effective at 0.5% level. Results of the ability of these adsorbents at level of 0.5% (w/v) to adsorb AFB(1) and FB(1) in malt extract spiked with 50, 100 and 200 ppb indicated that the capability of adsorbing of HSCAS ranged from 98.5% to 98.9% and 88.2% to 91.9% for AFB(1) and FB(1) respectively. Whereas, the capability of adsorbing of EM ranged from 98.1% to 98.7% and 88.2% to 92.5% for AFB(1) and FB(1) respectively.

Antioxidants and radical scavenging properties of vegetable extracts in rats fed aflatoxin-contaminated diet.

The present study evaluated the protection role of garlic, cabbage, and onion extracts against the toxic effects of aflatoxin. One hundred and twenty mature male Sprague-Dawley rats were randomly assigned to eight experimental groups and treated for 15 days with extracts with or without aflatoxin. Blood samples were collected from all animals from the retro-orbital venous plexus at the end of the experimentation period for biochemical analysis. Livers and kidneys were removed at the end of the treatment period for determination of glutathione, malondialdehyde, and superoxide dismutase. The results indicated that animals treated with aflatoxin showed significant signs of aflatoxicosis. Extracts alone had insignificant effects on all parameters tested, whereas cotreatment with aflatoxin and extracts resulted in a significant improvement in all parameters; moreover, garlic extract was found to be the most effective in the prevention of aflatoxin-induced toxicity and free radical generation in rats.

Distribution of aflatoxins in product and by-products during glucose production from contaminated corn.

Aflatoxins are known to be hepatotoxic, carcinogenic, and teratogenic. A positive correlation has been established between the consumption of aflatoxin-contaminated foods and the increased incidence of liver cancer worldwide. A survey of Egyptian corn and corn-based products and by-products shows that the majority of the samples had higher limits of aflatoxin. We have conducted experiments to determine the fate and distribution of aflatoxin during wet-milling process fractions and investigate the aflatoxin destruction during starch conversion to glucose syrup. The present results showed that about half of the aflatoxin content (48.1%) in the infected corn grain was found to be lost in steep liquor, depending upon the aflatoxin type, arranged in the order G1 > G2 > B1 > B2. After wet-milling aflatoxins were distributed into starch, gluten, fiber, and germ. Gluten, fiber, and germ were the most highly contaminated fractions. The loss of aflatoxin during process of starches reached 54.4% in steep water and water process. Although the gluten fraction represents only 9.6% of corn, the higher percentage (25.3%) of aflatoxin was found in this fraction, the fiber and germ account for nearly 29% of the milled corn and contain 11.6% of the aflatoxin. On the other hand, 8.7% of the total aflatoxins in start corn was found in starch fraction which accounts 61% of the milled corn. Aflatoxins G1 and G2 were found lost in higher concentrations compared to the aflatoxin B1 and B2. A higher percentage of AfG1 (86.35%) and AfG2 (78.36%) and a lower percentage of AfB1 (16.3%) and AfB2 (14.7%) were found in starch fraction. The conversion percent of contaminated starch was 89.5% compared with control starch. It can be concluded that aflatoxins were destroyed during starch conversion. Consequently, glucose syrup produced from contaminated starch was found aflatoxin-free.